Blitz pistachios until coarse; set aside.
Preheat oven to 180°C. Butter a shallow baking tray.
Layer 15 sheets of filo, brushing each generously with ghee.
Scatter pistachios and walnuts evenly on the 15th layer.
Continue layering remaining 15 sheets, brushing each with ghee; brush extra on top.
Cut Baklawa into squares or diamonds.
Bake 40 minutes until golden brown.
While baking, make syrup: combine sugar, water, lime juice, simmer 10 minutes.
Pour warm syrup over hot Baklawa.
Cool 2–3 hours or overnight. Decorate with crushed pistachios.
Serve and enjoy!